Question AMD Rembrandt/Zen 3+ APU Speculation and Discussion

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mikk

Diamond Member
May 15, 2012
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VCN 3.1.1 never existed in the first place, was a jebait as far as we're concerned. VCN4 is what Rembrandt features.

Also I've said it before, I'll say it again. Rembrandt exists for the premium thin and light market first, the thin and light gaming market second and everything else a very distant third.

Want a budget thin and light? Buy Alder Lake-M.

Want a high power gaming laptop? Buy Alder Lake-P.

Premium is a given because of the DDR5/LPDDR5 limitation this year. Yes seems like for a big iGPU increase in the mainstream/mass notebook segment we have to wait for next year.
 

uzzi38

Platinum Member
Oct 16, 2019
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Premium is a given because of the DDR5/LPDDR5 limitation this year. Yes seems like for a big iGPU increase in the mainstream/mass notebook segment we have to wait for next year.
If AMD decide to compete in that market sure.

When you have limited capacity and a top tier product, you focus on the premium category. It's kind of a given.
 
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LightningZ71

Golden Member
Mar 10, 2017
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The real kick in the family jewels is the 5850u. It gets +100Mhz max boost on the CPU (with a max power envelope of 15w) and a -200Mhz CUT to the iGPU! Why would I EVER choose the 5850u over an older, and likely cheaper SKU, that has the 5800u with more MHZ where it is most needed, the iGPU? you will NEVER feel that 100mhz on the CPU. If Barcelo is a refinement of Cezanne, why reduce performance unless you are deliberately sandbagging the product to protect the higher end of the stack? They could have made it LPDDR4X focused and pushed the iGPU to 2.1Ghz (which it is certainly capable of doing) and left the max CPU boost alone.
 

uzzi38

Platinum Member
Oct 16, 2019
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The real kick in the family jewels is the 5850u. It gets +100Mhz max boost on the CPU (with a max power envelope of 15w) and a -200Mhz CUT to the iGPU! Why would I EVER choose the 5850u over an older, and likely cheaper SKU, that has the 5800u with more MHZ where it is most needed, the iGPU? you will NEVER feel that 100mhz on the CPU. If Barcelo is a refinement of Cezanne, why reduce performance unless you are deliberately sandbagging the product to protect the higher end of the stack? They could have made it LPDDR4X focused and pushed the iGPU to 2.1Ghz (which it is certainly capable of doing) and left the max CPU boost alone.
Cezanne gets almost no bump to GPU performance from anywhere above 1.5GHz. Look at how little improvement there was over the 4800U.

Hell, scaling after even 1.1GHz is absolutely atrocious. It's not really that big a deal.
 

LightningZ71

Golden Member
Mar 10, 2017
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It does seem to scale better with LPDDR4X 4266. You don't see many of those SKUs, but, the few reviews I've seen show it being a measurable performance increase over comparable models with DDR4 3200.
 
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LightningZ71

Golden Member
Mar 10, 2017
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Something isn't adding up with the SKU leak... Lenovo's Thinkpad website for the new Z series models has...

AMD Ryzen™ PRO 6000 H Series Mobile Processors:
  • R9 PRO – 8 cores, 16 threads + 12 GPU cores
  • R7 PRO – 8 cores, 16 threads + 8 GPU cores
  • R5 PRO – 6 cores, 12 threads + 6 GPU cores
That R7 PRO with 8GPU cores... I didn't see that in the leaked slide... Could that be 2 segments with 2 activated WGPs instead of 2 segments with 3 WGPs like in the 12 CU model?

Or is it just a typo? Maybe a late change in segmentation that Lenovo didn't catch or AMD didn't correct on the slide?
 

Shivansps

Diamond Member
Sep 11, 2013
3,629
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The biggest problem with the IGP segmentation is that the whole point of the DDR5 premium is the IGP perf, and 6CU completely defeats that. What were they thinking? i dont get it. They had the chance to do 10 and 8CU SKUs, instead they go directly to 6, what may mean 2MB not 4MB of L2 as well.

¯\_(ツ)_/¯
 
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uzzi38

Platinum Member
Oct 16, 2019
2,323
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Something isn't adding up with the SKU leak... Lenovo's Thinkpad website for the new Z series models has...

AMD Ryzen™ PRO 6000 H Series Mobile Processors:
  • R9 PRO – 8 cores, 16 threads + 12 GPU cores
  • R7 PRO – 8 cores, 16 threads + 8 GPU cores
  • R5 PRO – 6 cores, 12 threads + 6 GPU cores
That R7 PRO with 8GPU cores... I didn't see that in the leaked slide... Could that be 2 segments with 2 activated WGPs instead of 2 segments with 3 WGPs like in the 12 CU model?

Or is it just a typo? Maybe a late change in segmentation that Lenovo didn't catch or AMD didn't correct on the slide?
PRO SKUs got different iGPU configs for Renoir if I remember correctly. This is just same thing again.
 

mikk

Diamond Member
May 15, 2012
3,635
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Even though 12CU performance is more a vaporware in the meaningful iGPU notebook segment, I would like to see a performance comparison with Vega 8 and Iris Xe 96EU, I wonder if we will see a test or something.
 

Abwx

Diamond Member
Apr 2, 2011
9,729
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The biggest problem with the IGP segmentation is that the whole point of the DDR5 premium is the IGP perf, and 6CU completely defeats that. What were they thinking? i dont get it. They had the chance to do 10 and 8CU SKUs, instead they go directly to 6, what may mean 2MB not 4MB of L2 as well.

¯\_(ツ)_/¯
That s an "incentive" to use their low end 12/16 CUs RDNA2 dGPU, both would suit a 6C SKU while the 16 CUs one would fit the 8C/8CUs part.
 
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tamz_msc

Diamond Member
Jan 5, 2017
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Strange as I have played with my brother's HP laptop with Ryzen 5800U just two weeks ago ... ;)
He bought it for coding and he was blown away by the speedup compared to Ryzen 4500U, like 4X+ faster.
Is it an HP Pavilion Aero? Because that's one of the three or four laptops with the 5800U that is available in my country.
 
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Shivansps

Diamond Member
Sep 11, 2013
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Even though 12CU performance is more a vaporware in the meaningful iGPU notebook segment, I would like to see a performance comparison with Vega 8 and Iris Xe 96EU, I wonder if we will see a test or something.
Its going to be faster than Vega 8, specially the Vega 8 sku below it that has a reduced IGP clock boost vs the old gen.
Against a DDR5 XE 96EUs i petty sure Intel wins that one.
 

eek2121

Golden Member
Aug 2, 2005
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6800U will have zero real availability, just like 5800U and 4800U before it.
Not necessarily. Rembrandt is on 6nm. Zen 3 is on 7nm, and Zen 4 is on 5nm. AMD is splitting their product stack up between different nodes, which should increase supply barring no other constraints. Right now, EVERYTHING is on 7nm.

I just bought a laptop, but if a new chip provides decent uplift, and we can get some light-ish laptops with a 5980HS and an AMD GPU, they will get my money (again). My daughter wants a gaming laptop anyway, so I can give her my old one. :D
 

Abwx

Diamond Member
Apr 2, 2011
9,729
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136
Cinebench comparison point to 5.6% better ST IPC than Zen 3, that s about twice the uplift they got from Zen to Zen+.

Also the MT improvement is too big for the 6nm process being the main reason, so there s surely also a bump in MT IPC.
 

Bigos

Member
Jun 2, 2019
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DDR5 might be the reason the MT performance increases so much (besides 6nm and power optimizations of course). It offers higher bandwidth and parallelism with 2x as many channels.

Or maybe something in the core or L3 was tweaked when it was being ported from N7 to N6?
 

mikk

Diamond Member
May 15, 2012
3,635
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AMD claimed double the performance at 1080p for the 6800U vs the 5800U.

5800U DDR4-3200 22-22-22 vs 6800U LPDDR5-6400 19-15-17 :laughing:
5800U 15W vs 6800 28W :laughing:
Zero about the Iris Xe device, probably DDR4
Based on testing by AMD as of 12/14/2021. CPU performance evaluated with a geomean of 9 multi-threaded content creation and CPU tests. GPU performance evaluated with 3DMark® Time Spy. System configuration for Ryzen™ 7 5800U CPU/GPU performance: HP ProBook 635 Aero G8 configured with 2x8GB DDR4-3200 (22-22-22), Windows® 11 22000.282, Samsung 980 Pro 1TB SSD, 15W nominal processor TDP, GPU driver 27.20.21026, BIOS T83. System configuration for Ryzen™ 7 6800U CPU/GPU performance: AMD reference motherboard configured with 4x4GB LPDDR5-6400 (19-15-17), Windows® 11 22000.282, Samsung 980 Pro 1TB SSD, 28W nominal processor TDP, GPU driver 30.0, BIOS TRM0081D. RMB-13


But it's AMD, it's fine. If Intel does this the forum explodes.
 

Abwx

Diamond Member
Apr 2, 2011
9,729
1,985
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DDR5 might be the reason the MT performance increases so much (besides 6nm and power optimizations of course). It offers higher bandwidth and parallelism with 2x as many channels.

Or maybe something in the core or L3 was tweaked when it was being ported from N7 to N6?
RAM speed improvement has about zero influence for CB.
 

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